[SYNAPSE-342] Improvements for issues found during Performance and Load testing

• Type: Bug
• Status: Resolved
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 1.2-beta1
• Fix Version/s: 1.2
• Component/s: Core, Transports
• Assignee: Asankha Chamath Perera
• Reporter: Asankha Chamath Perera
• Created: 04/Jun/08 04:20
• Updated: 04/Jun/08 04:30
• Resolved: 04/Jun/08 04:30

Description

During load testing, I encountered an error for about once in 300,000 to 400,000 requests of 1K, iterating 1000 messages at 80 user concurrency. The issue resulted in a 'Transfer-Encoding header already present' error, but the cause was the Axis2FlexibleMEPClient.send()'s last two lines, which needs to switch the request to skip the 202 accepted message with the mepclient.execute() which could take time even with async NIO sender

On performance front, I came across a few places where we used Axiom's serialize() method instead of serializeAndConsume() - which was due to a bad merge from the 1.1 codebase

I am also adding a connection.isStale() check before returning a keepalive connection for reuse to improve stability